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纳米晶体的性质不仅由表面原子所占的大的组分决定,而且由晶粒表面的晶相结构决定,因此对纳米晶体的表面的晶相结构的了解是很有必要的.氧化锌具有独特的物理和化学性质,所以它被认为是一种比较有应用前景的3维有序组装结构的基本构造单元.利用胶体化学法和尺寸选择制备了4~5 nm大小的PVP包覆的氧化锌纳米晶体.用X射线衍射(XRD),高分辨透射电镜(HR-TEM),选区电子衍射(SAED),紫外可见吸收光谱(ABS)和荧光光谱(PL)对氧化锌的晶体结构和表面晶相结构进行表征,发现氧化锌晶体是结晶很好的红锌矿结构并且尺寸是单分散的.XRD,ABS和HR-TEM的测试结果都表明氧化锌晶体的尺寸是4.5 nm.用HR-TEM和相应的傅立叶转换(FFT)对氧化锌的形貌和表面晶相进行研究,发现氧化锌晶体具有截角六面体形状,分别被{0001},{0 1 1 0},和{0 1 1 1}晶面包围.氧化锌的荧光光谱出现了两个典型的荧光发射,位置分别在362 nm和527 nm,来源于带边发射和缺陷发光.另外在400 nm和470 nm处也出现了弱的荧光发射,这可能与氧化锌的多面体形貌或者PVP的存在有关.
The properties of nanocrystals are not only determined by the large components of the surface atoms, but also by the crystal structure of the grain surface, so understanding of the crystal structure of the nanocrystal surface is necessary.Zinc oxide has a unique So it is considered as a more basic structural unit of the three-dimensional ordered assembly structure with potential applications.The colloidal chemistry method and size selection were used to prepare PVP-coated zinc oxide with the size of 4 ~ 5 nm Nanocrystals were prepared by the X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED), ultraviolet absorption spectroscopy (ABS) and fluorescence spectroscopy (PL) Phase structure and found that the zinc oxide crystal is a well-crystallized zincite structure and the size is monodisperse.XRD, ABS and HR-TEM test results show that the size of the zinc oxide crystals is 4.5 nm.With HR-TEM And the corresponding Fourier Transform (FFT) were used to study the morphologies and surface phases of zinc oxide. It was found that the zinc oxide crystals have the shape of a truncated hexahedron and are respectively represented by {0001}, {0 1 1 0}, and {0 1 1 1} } Crystal face surrounded by zinc oxide fluorescence spectrum appeared two typical Fluorescence emission at 362 nm and 527 nm, respectively, originated from band edge emission and defect luminescence, and weak fluorescence emission also occurred at 400 nm and 470 nm, which may be related to the polyhedron morphology of zinc oxide or the presence of PVP related.